Abstract

The aberration-corrected scanning transmission electron microscope allows probes to be formed with less than 1-Å diameter, providing sufficient sensitivity to observe individual Hf atoms within the passivating layer of a alternative gate dielectric stack. Furthermore, the depth resolution is sufficient to localize the atom positions to half-nanometer precision in the third dimension. From a through-focal series of images, we demonstrate a three-dimensional reconstruction of the Hf atom sites, representing a three-dimensional map of potential breakdown sites within the gate dielectric.

Received 26 April 2005Accepted 06 June 2005Published online 14 July 2005

Acknowledgments:

M.F. Chisholm is gratefully acknowledged for his contributions to the manuscript. This research was sponsored by the Laboratory Directed Research and Development Program of ORNL, managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725 and by an appointment to the ORNL postdoctoral Research Program administered jointly by ORNL and ORISE. K.v.B. greatly appreciates funding from the Alexander-von-Humboldt Foundation.